M Tazli Azizan
Universiti Teknologi PETRONAS, Chemical Engineering, Faculty Member
- Imperial College London, Chemical Engineering, Graduate Studentadd
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Abstract Methane can be converted into other useful products such as H2 and liquid fuels to reduce its environmental impact. Due to majorly high energy requirements and the endothermic nature of the reforming process, catalysts are... more
Abstract Methane can be converted into other useful products such as H2 and liquid fuels to reduce its environmental impact. Due to majorly high energy requirements and the endothermic nature of the reforming process, catalysts are essential. The catalyst preparation method is one of the aspects that can improve the catalytic performance by enhancing the catalyst’s physicochemical properties. These methods alter the metal-support interaction, thereby changing the kinetics of the catalyst which can result in enhanced productivity, reduced cost, and optimized energy requirements. This review compares state-of-the-art catalyst preparation methods and discusses their effects on the physicochemical properties of the catalysts used in methane reforming processes.
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Abstract This article discusses the Focus Group Discussion (FGD) in the context of the research project investigating educators’ transition traditional teaching to active learning. Engineering education researchers are increasingly... more
Abstract This article discusses the Focus Group Discussion (FGD) in the context of the research project investigating educators’ transition traditional teaching to active learning. Engineering education researchers are increasingly interested in qualitative data analysis to study social phenomenon on teaching and learning. We describe the research design in phases that show the pragmatic approach to conduct FGD. This study employed FGD using Critical Discourse Analysis (CDA) as the methodology to develop an interview protocol. We present an analysis of a two-hour interview conducted with a group of lecturers at one of the university in Malaysia using a set of interview protocol. The interview protocol was developed following the principle of CDA to provide answers on the aspect of social practices surrounding the implementation of active learning. With CDA, the FGD interview focused on the issues, obstacles to solve the issues, role of issues in the broader context and ways for the issues to be solved. The findings revealed that FGD enables the data collection and analysis to investigate complex belief on the concept and implementation of active learning. The educators responded positively to interactive active learning activities as a medium for instruction. In addition, the analyses indicate that educators’ resistance emerged from the conflicting imposter syndrome among resistance educators. Uncomfortable with the transition from teacher-centred to student-centred learning, many of them have self-doubt on what is meant by active learning. CDA shows that they have developed a feeling of competence despite evidence of being incompetent in active learning. Further to this, we begin to identify educators’ epistemic knowledge on active learning which leads to the imposter syndrome.
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A flipped classroom has introduced a new way of learning where students need to familiarize with the content before the in-class session so that more time would be allocated for class activities and face-to-face engagement with the... more
A flipped classroom has introduced a new way of learning where students need to familiarize with the content before the in-class session so that more time would be allocated for class activities and face-to-face engagement with the lecturer. In this study, an implementation of a partially flipped classroom for over one semester of enrolment of Transport Phenomena course has been conducted to look at how far the flipped classroom is effective in helping the students to improve their results. Learning materials such as videos, notes, and postcards are given to students before the commencement of the class. Meanwhile, group activities such as informal cooperative learning activities, i.e. think-pair-share, Intermittent focused discussion, etc. were also implemented during the class. The results showed improved marks for test, assignment, and quiz obtained by students as a comparison before implementation of a flipped classroom. For instance, 61 % of the students improved in their test marks, 70% improved in the assignment, and, 31 % improved in the quiz. Students were also improved in their communication skill and team work amongst them. In a nutshell, a flipped classroom method can help students in enhancing their way of learning, and they will eventually become independent learners which is one of the primary attributes of UTP graduates.
The aqueous phase reforming (APR) of glycerol was studied using sonochemically synthesized 10%Ni-x%Ca/ZrO2 catalysts (where x = 0, 0.5, 3, and 5) for the production of value-added liquid products. The APR reaction was performed in a batch... more
The aqueous phase reforming (APR) of glycerol was studied using sonochemically synthesized 10%Ni-x%Ca/ZrO2 catalysts (where x = 0, 0.5, 3, and 5) for the production of value-added liquid products. The APR reaction was performed in a batch reactor under the following conditions: 20 bar, 230 °C 450 rpm, and 1 h of reaction time. The synthesized catalysts were characterized using XRD, FESEM, BET, and H2-TPR to observe the effect of Ca doping on the physio-chemical properties of the catalysts. The results revealed that, at higher Ca loading, the catalysts experienced serious particles’ agglomeration, which resulted in a larger particles’ size, smaller surface area, and smaller pore volume owing to uneven distribution of the particles. The characterization results of the catalysts confirmed that the Us catalysts have a slightly higher surface area, pore volume, and pore size, as well as highly reducible and fine crystalline structure, compared with WI catalysts. The catalytic performance...
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The outlook and incentive toward the development of cleaner and sustainable energy resources are growing worldwide due to the rise of fossil fuel price, depletion of petroleum resources, and environmental protection issues. Therefore, the... more
The outlook and incentive toward the development of cleaner and sustainable energy resources are growing worldwide due to the rise of fossil fuel price, depletion of petroleum resources, and environmental protection issues. Therefore, the development of biofuel technologies, that is, bio-based fuels are projected to play an essential role in the foreseeable transportation and automotive industries. Synthetic biofuels from agricultural-based origins such as biohydrogen, biogas, biogasoline, biodiesel, and green diesel will emerge as prospective fuels of tomorrow due to their excellent fuel properties and environmental friendly attributes. Thus, this book chapter focuses on the challenges and drawbacks of the existing liquid and gaseous biofuel production technologies. To overcome these challenges, advanced biofuel technologies such as steam gasification, ultrasonic and microwave intensification for biodiesel production, catalytic cracking and hydrodeoxygenation of vegetable oils for ...
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The society with positive values made the world a better place to live. This also include the engineers at the workplace. Studies have shown that engineering students are less empathetic and prone to be dishonest academically, with the... more
The society with positive values made the world a better place to live. This also include the engineers at the workplace. Studies have shown that engineering students are less empathetic and prone to be dishonest academically, with the current curriculum design fixing this issue only introducing the students with few humanities and social sciences courses. This study investigated the adoption of student centered learning methods to nurture positive values among the 2nd year chemical engineering students, enrolled in a cooperative based group environment. The meta-reflection of the students highlighted that there were a lot of positive values emerged after one semester activities completed among the students. The students learnt about being assertive, respecting each other's opinion, perseverance and grit, as well as empathy.
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Hydrodeoxygenation is most considered route for up-gradation of biodiesel and triglycerides towards direct conversion into diesel range hydrocarbon (green diesel). Heterogeneous (Ni-Mo/γ-Al2O3 catalysts) catalysis offers more promising... more
Hydrodeoxygenation is most considered route for up-gradation of biodiesel and triglycerides towards direct conversion into diesel range hydrocarbon (green diesel). Heterogeneous (Ni-Mo/γ-Al2O3 catalysts) catalysis offers more promising routes for transformation of biomass into value added bio-chemicals more likely selective hydrocarbons in a resourceful approach. In this study, the Ni-Mo/γ-Al2O3 type catalysts were investigated for the hydrodeoxygenation of rubber seed oil for the diesel range hydrocarbons (n-C15-n-C18). Monometallic solid acid catalysts (Ni/γ-Al2O3) and bimetallic (Ni-Mo/γ-Al2O3) catalysts were tested for HDO reaction at 340 oC, 21 bar, H2/oil ratio 150 Nm3/m3 using 5 g, WHSV = 10 h-1 for 5 h time on stream in tubular fixed bed reactor (pilot scale). Among the sonochemically synthesized catalysts, 3 wt. % Ni/γ-Al2O3 showed the higher catalytic activity up to 15.4 wt. % and bimetallic Ni-Mo/γ-Al2O3 was perceived to be more active with 15.35 wt.% diesel range (C15-C1...
Article history: Received 31 December 2014 Received in revised form 26 January 2015 Accepted 28 January 2015 Available online 11 February 2015
Oil palm biomass residues in Southeast Asia, which are underutilized, can be converted into solid fuel if they are torrefied. In this case, flue gas in palm oil mills may be economical gas and thermal energy sources of torrefaction. This... more
Oil palm biomass residues in Southeast Asia, which are underutilized, can be converted into solid fuel if they are torrefied. In this case, flue gas in palm oil mills may be economical gas and thermal energy sources of torrefaction. This study aims to investigate the effects of oxygen (0, 9, 15 and 21 vol%) and carbon dioxide (0, 9, 15 and 21 vol%) in torrefaction gas towards torrefaction behavior of EFB, in specific calorific value and carbon content, the representative indices for solid fuel. The torrefaction temperature and time ranged 493-573 K and 30-90 min, respectively. In general, existence of oxygen resulted in higher carbon content, and thus higher calorific value. On the other hand, existence of carbon dioxide did not exhibit such an enhancement effect except for 30 min torrefaction of at the highest temperature of 573 K.
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Abstract In general, aqueous phase reforming (APR) is used to convert glycerol into 1,3-propanediol (1,3-PDO), nonetheless, studies have shown a low selectivity of 1,3-PDO. Therefore, this study aims to optimize the selectivity of 1,3-PDO... more
Abstract In general, aqueous phase reforming (APR) is used to convert glycerol into 1,3-propanediol (1,3-PDO), nonetheless, studies have shown a low selectivity of 1,3-PDO. Therefore, this study aims to optimize the selectivity of 1,3-PDO by varying the ultrasound (Us) irradiation process time between 10 and 50 min during catalyst preparation. This is to investigate the effect on the physiochemical properties and activity of the catalyst. Ni–Mo/Al2O3 catalysts were prepared using a sonochemical method and was characterized using Brunauer-Emmett-Teller (BET), X-ray Powder Diffractometer (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Hydrogen Temperature-programmed Reduction (H2-TPR). Characterization results revealed that there were significant improvements in physiochemical properties of catalysts by varying the Ultrasound (Us) irradiation time. Subsequently, all catalysts were screened using APR of glycerol for 1,3-PDO production using an Autoclave PREMEX reactor and the liquid products were analyzed to determine the selectivity of 1,3-PDO. From all the results, findings revealed that the catalyst prepared with 10 min of Us radiation time demonstrated a high catalytic performance and physiochemical properties while producing the highest concentration of 1,3-PDO with 954 ppm with a conversion of 38.6%. The outcomes have shown that sonochemical irradiation time conversely effects on the physiochemical properties of the catalysts and 1,3-PDO production.
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Global energy requirements are rising tremendously because of increasing urbanization and the human population. In the last few centuries, the consumption of fossil fuels has caused increased emissions of greenhouse gases resulting in... more
Global energy requirements are rising tremendously because of increasing urbanization and the human population. In the last few centuries, the consumption of fossil fuels has caused increased emissions of greenhouse gases resulting in environmental concerns like global warming, climatic change, and biodiversity loss. As a result, progress in sustainable energy has become the centre of attention in climatic change agenda and economic growth. Until now, various methods of renewable energy production have been extensively studied such as geothermal energy, wind energy, and solar energy. In addition to this, the utilization of biofuels from different sustainable sources are also being considered to reduce greenhouses gas emissions. New approaches and developments are still required for the creation of more sustainable, efficient, and affordable renewable energy systems and for the mitigation of global environmental threats. This special issue aims to advance novel developments in the su...
Research Interests: Environmental Science, Climate Change, Renewable Energy, Sustainability Indicators, Sustainability (Organisational Strategy), and 7 moreCorporate Sustainability, Environmental Sustainability, Sustainable Agriculture (Sustainability), Renewabel Energy, Tourism Sustainability, Sustainability, and Renewable Energy and Climate Change
Hydrodeoxygenation (HDO) is considered as a substantial path for cleaner production of fatty acids and triglycerides into diesel range hydrocarbons (DRHs) (C15–C18) generally identified as green diesel fuel. Heterogeneous catalysis... more
Hydrodeoxygenation (HDO) is considered as a substantial path for cleaner production of fatty acids and triglycerides into diesel range hydrocarbons (DRHs) (C15–C18) generally identified as green diesel fuel. Heterogeneous catalysis suggests a supplementary approach for the conversion of biomass into significant biochemicals possibly selective hydrocarbons by an inventive method. The present study reveals the optimization of reaction parameters for the process of HDO of rubber seed oil (RSO) over the transition metal NiMo/γ-Al₂O₃ (NMA) catalyst (designed via sonochemical co-impregnation approach) into DRHs, that is, n-C15-n-C18. The comprehensive studies have been performed to investigate the parametric effects employing response surface methodology using central composite design. The experimental design was conducted on the four most influential operating factors, namely, temperature within the range of 300–400 °C, weight hourly space velocity (WHSV) (1–3 h–¹), H₂/oil ratio (400–1000 N (cm³/cm³)), and pressure (30–80 bar), for triglyceride conversion and DRH yield. All the experimental runs were performed in continuous process using a fixed bed tubular reactor over the NMA catalyst. The product analysis showed that triglycerides are completely hydrodeoxygenated into DRHs with an optimum production of 84.94 wt % yield led by prime reaction conditions at a temperature of 400 °C, WHSV of 1 h–¹, pressure of 80 bar, and H₂/oil ratio of 400 N (cm³/cm³). The parametric interaction between temperature and WHSV has significantly influenced the diesel yield. The investigations validated that HDO tracked the corresponding reaction condition in competitive mode and obligated the diverse optimum and limiting reaction conditions. In addition, deactivation of the catalyst study was performed at the optimized reaction condition. The catalyst was found to be active until 18 h without bringing to sulfidization process with 80% diesel yield and 100% triglyceride conversion. The slight deactivation of the catalyst is observed, with a very small amount coke deposition even after 18 h of time on stream at the optimized reaction condition. The novelty of the present study lies in the performance of sonochemically synthesized catalyst for HDO of RSO to produce green diesel and to optimize the reaction condition and catalysts deactivation performance at optimized reaction conditions.
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Malaysian oil palm industry produces a significant amount of oil palm residue as solid wastes. These solid wastes are comprised of oil palm residue which contains the stem, fronds from the farms, empty fruit bunch (EFB), mesocarp fibre... more
Malaysian oil palm industry produces a significant amount of oil palm residue as solid wastes. These solid wastes are comprised of oil palm residue which contains the stem, fronds from the farms, empty fruit bunch (EFB), mesocarp fibre (MF), and palm kernel shell (PKS) from the oil palm–processing factories. These residues are not successfully reused for other purposes, and the current dumping methods can possibly trigger unfavourable effects to the environment. As oil palm residues are a readily available waste biomass, it has a high potential to be converted into valuable energy-derived products. Hydrothermal carbonization (HTC), which is a thermochemical process, is a method used to treat biomass to produce hydrochar under hot-compressed water. Oil palm residues (palm leaves, palm fronds, and palm shell) were used as the feedstock for producing carbonaceous hydrochar. The key objective of this study is to examine the effect of the reaction temperature, residence time, and acid catalysts on the HTC process. HTC of oil palm residues was optimized at different operating temperatures from 140 to 300 °C and different reaction times between 30 and 240 minutes with a biomass-to-water ratio of 1:10 wt%. Acid catalysts such as citric acid and ascorbic acid were used for the HTC process. The hydrochar produced is further characterized using heating value and elemental and Fourier transform infrared (FTIR) analysis. The yield of hydrochar reduces with the rise of temperature and time but it increases in the presence of acid catalysts. The carbon content of hydrochar is observed to be between 44.36 and 49.50%. The FTIR analysis showed that a high intensity at 1423 cm−1 indicates a high content of lignin and cellulose in the hydrochar. A considerable decrease in the H/C and O/C atomic ratio shows that the dehydration and decarboxylation take place during the HTC process.
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Malaysian oil palm industry produces a significant amount of oil palm residue as solid wastes. These solid wastes are comprised of oil palm residue which contains the stem, fronds from the farms, empty fruit bunch (EFB), mesocarp fibre... more
Malaysian oil palm industry produces a significant amount of oil palm residue as solid wastes. These solid wastes are comprised of oil palm residue which contains the stem, fronds from the farms, empty fruit bunch (EFB), mesocarp fibre (MF), and palm kernel shell (PKS) from the oil palm–processing factories. These residues are not successfully reused for other purposes, and the current dumping methods can possibly trigger unfavourable effects to the environment. As oil palm residues are a readily available waste biomass, it has a high potential to be converted into valuable energy-derived products. Hydrothermal carbonization (HTC), which is a thermochemical process, is a method used to treat biomass to produce hydrochar under hot-compressed water. Oil palm residues (palm leaves, palm fronds, and palm shell) were used as the feedstock for producing carbonaceous hydrochar. The key objective of this study is to examine the effect of the reaction temperature, residence time, and acid ca...
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Global energy requirements are rising tremendously because of increasing urbanization and the human population. In the last few centuries, the consumption of fossil fuels has caused increased emissions of greenhouse gases resulting in... more
Global energy requirements are rising tremendously because of increasing urbanization and the human population. In the last few centuries, the consumption of fossil fuels has caused increased emissions of greenhouse gases resulting in environmental concerns like global warming, climatic change, and biodiversity loss. As a result, progress in sustainable energy has become the centre of attention in climatic change agenda and economic growth. Until now, various methods of renewable energy production have been extensively studied such as geothermal energy, wind energy, and solar energy. In addition to this, the utilization of biofuels from different sustainable sources are also being considered to reduce greenhouses gas emissions. New approaches and developments are still required for the creation of more sustainable, efficient, and affordable renewable energy systems and for the mitigation of global environmental threats. This special issue aims to advance novel developments in the su...
Research Interests: Environmental Science, Climate Change, Renewable Energy, Sustainability Indicators, Sustainability (Organisational Strategy), and 7 moreCorporate Sustainability, Environmental Sustainability, Sustainable Agriculture (Sustainability), Renewabel Energy, Tourism Sustainability, Sustainability, and Renewable Energy and Climate Change
The catalytic steam reforming of oxygenated hydrocarbons has been holding an interest in scientific societies for the past two decades. The hydrogen production from steam reforming of glycerol, ethanol and other oxygenates such as... more
The catalytic steam reforming of oxygenated hydrocarbons has been holding an interest in scientific societies for the past two decades. The hydrogen production from steam reforming of glycerol, ethanol and other oxygenates such as ethylene glycol and propylene glycol are more suitable choice not just because it can be produced from renewable sources, but it also helps to decrease the transportation fuel price and making it more competitive. In addition, hydrogen itself is a green fuel for the transportation sector. The studies on the production of hydrogen from various reforming technologies revealed a remarkable impact on the environmental and socio-economic issues. Researchers became more focused on glycerol steam reforming (GSR), ethanol steam reforming (ESR) and other oxygenates to investigate the catalyst suitability, their kinetics and challenges for the sustainability of the oil and gas production. In the present work, the authors critically addressed the challenges and strat...
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The objectives of this study were to investigate the most thermodynamically favoured reaction pathway during APR of sorbitol. The thermodynamic analysis of APR of sorbitol was studied using ASPEN Plus V8.0 by applying Gibbs free energy... more
The objectives of this study were to investigate the most thermodynamically favoured reaction pathway during APR of sorbitol. The thermodynamic analysis of APR of sorbitol was studied using ASPEN Plus V8.0 by applying Gibbs free energy minimization principle, operating at different temperatures (300–800 K), pressure (10–30 bar) and sorbitol concentration (1%, 3%, 5%, 10%, 15% and 20%). The simulation model was validated by comparing the results with the existing work conducted by Serentis and Tsiakaras. The results obtained show that the mol fraction and trend of H2, CO2 and CH4 for both cases are almost similar to the existing work. Therefore the simulation model was validated. Five main reaction pathways of APR of sorbitol were identified and intermediates of each reaction pathway were defined according to their stages and their composition was analyzed. The result obtained show that the decarbonylation reaction (pathway 2) is the most thermodynamically favoured pathway with a tot...
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Abstract The process optimization of hydrodeoxygenation of rubber seed oil was investigated on diesel range hydrocarbons selectivity and conversion of reaction intermediates. The comprehensive investigation has been performed on effects... more
Abstract The process optimization of hydrodeoxygenation of rubber seed oil was investigated on diesel range hydrocarbons selectivity and conversion of reaction intermediates. The comprehensive investigation has been performed on effects of reaction parameters and optimization condition using Response Surface Methodology. The experimental runs were carried out over four operating parameters i.e. temperature (300-400 °C), pressure (30–80 bar), weight hourly space velocity (WHSV) (1-3 h−1) and H2: oil ratio (400–1000 N cm3/cm3). The reaction intermediates were investigated over optimized reaction parameters for 5 h time on stream. The current study revealed that triglycerides are completely converted into diesel range hydrocarbons to produce hydrodeoxygenation (HDO) selectivity (C16 + C18) of (19.1 wt%) and decarboxylation (DCOx) selectivity (C16 + C18) of (81.7 wt%) under optimized reaction condition at the temperature of 400 °C, pressure 80 bar, WHSV = 1 h−1, and H2: oil ratio 400 N(cm3/cm3). Among all the variables temperature and weight hourly space velocity have significantly influenced the hydrodeoxygenation selectivity. In contrast, where the increase in temperature and pressure dropped the decarboxylation selectivity. H2: oil ratio was observed with significant effect on conversion of transition state of intermediates to stable state of intermediates at optimized condition. The ANOVA analyses demonstrated that HDO selectivity competitively followed on respective reaction condition.
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Abstract The comprehensive studies have been accomplished to examine the effect of Ni loading over H-Y zeolite for hydrodeoxygenation (HDO) of crude rubber seed oil. Monometallic Ni/H-Y zeolite catalysts were synthesized via wet... more
Abstract The comprehensive studies have been accomplished to examine the effect of Ni loading over H-Y zeolite for hydrodeoxygenation (HDO) of crude rubber seed oil. Monometallic Ni/H-Y zeolite catalysts were synthesized via wet impregnation method with different wt. % of Ni i.e. (3, 12 and 15 wt.% Ni) doped on H-Y zeolite. Field Emission Scanning Electron Microscopy (FESEM) coupled with Electron Dispersive X-ray analysis (EDX), X-ray Diffraction (XRD), Brunauer–Emmett–Teller (BET) Surface Area and Temperature Programmed Reduction (H2TPR) techniques were used to study the textural properties of the hydrocracking catalysts. The physiochemical characterization of synthesized catalysts revealed that the metal oxides were homogenously dispersed over the support with higher surface area and low reduction temperature. The hydrodeoxygenation of rubber seed oil was performed in fixed bed tubular reactor at 350°C, 35 bar H2 pressure, H2: Oil ratio 1000 N (cm3/cm3), and weight hour space velocity (WHSV) =1 h-1. The liquid products analysis revealed that the diesel range hydrocarbons (C15-C18) yield increased with increasing Ni loading. 15 wt.% Ni/H-Y zeolite showed comparatively higher yield of diesel range hydrocarbons i.e.(30 wt.%) among all the synthesized catalysts. All the catalysts showed >99% triglycerides conversion into diesel range hydrocarbons and other oxygenated intermediates. The selectivity for diesel range hydrocarbons was obtained as follows C15 (14.5 wt.%), C16 (6.8 wt.%), C17 (10.4 wt.%) and C18 (2.4 wt.%) for 15 wt.% Ni/H-Y zeolite catalyst. Mostly, all catalysts produced lower alkanes due to high acidity and hydrocracking property of H-Y zeolite. The HDO activity showed that H-Y zeolite catalyst is more favorable for hydrocracking of crude vegetable oil to produce lower alkanes, compared to diesel range hydrocarbons due to its high acidity.
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Abstract In recent times, glycerol has been employed as feedstock for the production of syngas (H2 and CO) with H2 as its main constituent. This study centers on dry reforming of glycerol over Ag-promoted Ni/Al2O3 catalysts. Prior to... more
Abstract In recent times, glycerol has been employed as feedstock for the production of syngas (H2 and CO) with H2 as its main constituent. This study centers on dry reforming of glycerol over Ag-promoted Ni/Al2O3 catalysts. Prior to characterization, the catalysts were synthesized using the wet impregnation method. The reforming process was carried out using a fixed bed reactor at reactor operating conditions; 873–1173 K, carbon dioxide to glycerol ratio of 0.5 and gas hourly space velocity (WHSV) in the range of 14.4 ≤ 72 L gcat−1 h−1). Ag (3)-Ni/Al2O3 gave highest glycerol conversion and hydrogen yield of 40.7% and 32%, respectively. The optimum conditions which gave highest H2 production, minimized methane production and carbon deposition were reaction temperature of 1073 K and carbon dioxide to glycerol ratio of 1:1. This result can attributed to the small metal crystallite size characteristics possessed by Ag (3)–Ni/Al2O3, which enhanced metal dispersion in the catalyst matrix. Characterization of the spent catalyst revealed the formation of two types of carbon species; encapsulating and filamentous carbon which can be oxidized by O2.
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Abstract Hydrodeoxygenation (HDO) of vegetable oil is one of the promising key processes designed for a possible convenient method for automotive clean fuel production. The HDO of rubber seed oil into diesel range hydrocarbon over... more
Abstract Hydrodeoxygenation (HDO) of vegetable oil is one of the promising key processes designed for a possible convenient method for automotive clean fuel production. The HDO of rubber seed oil into diesel range hydrocarbon over non-sulphided monometallic (Ni/γ-Al2O3 and Mo/γ-Al2O3) catalysts were investigated. The catalysts were synthesized via conventional wet impregnation method using 3 wt.%, 12 wt.% and 15 wt.% Ni and Mo loading over γ-Al2O3 support, to examine the influence of metal loading on catalytic activity, coke deposition, and reaction routes. The synthesized catalysts were subjected to characterization techniques including XRD, FESEM coupled with EDX, BET, TEM, TGA, ICP-OES and H2TPR. All the catalysts were tested for HDO reaction at 623.15 K, 3.5 MPa, H2/oil of 1000 N (cm3/cm3) with WHSV = 1 h−1 in a continuous flow fixed bed tubular reactor. The hydrocarbon products were analyzed using gas chromatography, and intermediates were identified using GC–MS. The Ni supported catalysts showed comparatively higher surface area, small particle size, homogeneous dispersion of particles, higher crystallinity and lower reduction temperature, low coke deposition. Proposed reaction mechanism suggests the decarboxylation (DCO2) reaction occurred mainly over Ni supported catalysts. Whereas, higher Ni loading reduced the extent of decarboxylation (DCO2) reaction. Additionally, Mo supported catalysts allowed the deoxygenation reaction to occur and higher Mo loading enhanced the extent of hydrodeoxygenation (HDO). The triglycerides conversion for all the catalysts was 99.9%. The catalysts with higher metal loading showed overall higher catalytic activity for hydrodeoxygenation of RSO. 15 wt.% Ni loading produced higher hydrocarbon yield (55.1 wt.%) whereas, 15 wt.% Mo loading produced up to 61.7 wt.%. Mo comparatively produced high amount of C16 (15.7 wt.%), and C18 (30.7 wt.%) hydrocarbons. Whereas, Ni produced mainly C15 (20.9 wt.%) and C17 (20.3 wt.%) hydrocarbons. Significant findings were observed on hydrocarbon yield, intermediates, and amount of coke formation. Mo supported catalysts shows significant HDO activity with less concentration of oxygenated component in the mixture. Besides Mo supported catalysts exhibit the high amount of coke deposition compared to Ni supported catalysts.
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Abstract To produce well-rounded students with excellent teamwork skills and creativity, one of the teaching strategies that can be adopted in engineering education is cooperative learning. This study aims to enhance creativity, deep... more
Abstract To produce well-rounded students with excellent teamwork skills and creativity, one of the teaching strategies that can be adopted in engineering education is cooperative learning. This study aims to enhance creativity, deep learning and improve teamwork skills among the third-year chemical engineering students using cooperative learning strategy. Complex instruction method is adopted by instructing the students to develop a board game and embed technical based questions, which are related to kinetic and reactor design subject (KRD) and other two courses, as part of the integrated project. The reflections from the students, the findings from the survey and the evaluation of the students’ outputs, suggested that though they enjoyed the activity, it was a challenging and a complex task, which in turn provoked their thoughts, creativity and made them acquired teamwork skills.
Research Interests: Engineering and Education
Hydrodeoxygenation is one of the promising technologies for the transformation of triglycerides into long-chain hydrocarbon fuel commonly known as green diesel. The hydrodeoxygenation (HDO) of rubber seed oil into diesel range (C15-C18)... more
Hydrodeoxygenation is one of the promising technologies for the transformation of triglycerides into long-chain hydrocarbon fuel commonly known as green diesel. The hydrodeoxygenation (HDO) of rubber seed oil into diesel range (C15-C18) hydrocarbon over non-sulphided bimetallic (Ni-Mo/γ-Al2O3 solid catalysts were studied. The catalysts were synthesized via wet impregnation method as well as sonochemical method. The synthesized catalysts were subjected to characterization methods including FESEM coupled with EDX, XRD, BET, TEM, XPS, NH3-TPD, CO-chemisorption and H2-TPR in order to investigate the effects of ultrasound irradiations on physicochemical properties of the catalyst. All the catalysts were tested for HDO reaction at 350 °C, 35 bar, H2/oil 1000 N (cm3/cm3) and WHSV = 1 h-1 in fixed bed tubular reactor. The catalyst prepared via sonochemical method showed comparatively higher specific surface area, particles in nano-size and uniform distribution of particle on the external surface of the support, higher crystallinity and lower reduction temperature as well as higher concentration of Mo4+ deoxygenating metal species. These physicochemical properties improved the catalytic activity compared to conventionally synthesized catalyst for HDO of rubber seed oil. The catalytic performance of sonochemically synthesized Ni-Mo/γ-Al2O3 catalyst (80.87%) was higher than the catalyst prepared via wet impregnation method (63.3%). The sonochemically synthesized Ni-Mo/γ-Al2O3 catalyst is found to be active, produces 80.87 wt% of diesel range hydrocarbons, and it gives high selectivity for Pentadecane (18.7 wt%), Hexadecane (16.65 wt%), Heptadecane (24.45 wt%) and Octadecane (21.0 wt%). The product distribution revealed that the deoxygenation reaction pathway was preferred. Higher conversion and higher HDO yield in this study are associated mainly with the change in concentration ratio between oxidation states of molybdenum (Mo4+, Mo5+, and Mo6+) on the external surface of the catalyst due to ultrasound irradiation during the synthesis process. Consequently, the application of sonochemically synthesized non-sulphided catalysts favored mainly hydrodeoxygenation of diesel range hydrocarbon.
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The catalytic upgrading of vegetable oil to green diesel is one of the distinct research subjects in biorefineries. The catalytic conversion of triglycerides entails the method of hydrotreating such as hydrogenation, hydrodeoxygenation,... more
The catalytic upgrading of vegetable oil to green diesel is one of the distinct research subjects in biorefineries. The catalytic conversion of triglycerides entails the method of hydrotreating such as hydrogenation, hydrodeoxygenation, decarboxylation and decarbonylation as well as isomerization. The product derived is renewable green diesel (straight chain hydrocarbon), of which its production addresses the sustainability of the future energy. The main challenges faced by hydrodeoxygenation are the selection and synthesis of suitable catalysts, selection of appropriate feedstocks, optimization of the thermodynamic parameters, and the reaction pathways. The literature on the selection of feedstock and model compounds is discussed in the sub-section. This review also includes the evaluation on several potential catalysts such as bimetallic solid acid, sulphided, non-sulphided, nitrides, phosphided, isomerization and hydrocracking catalysts as well as the noble metal catalysts. The selection of the metal supports catalysts, the catalyst designed practice and the overall performance is also reviewed and discussed. The most common supports used for the hydrodeoxygenation is solid acid composites such as Al2O3 and zeolites. In addition, the promoters tested yield different results with different reaction mechanisms demonstrated. The research on the hydrodeoxygenation pathways and the product distribution related with all kinds of catalysts are also addressed. In addition, the advancement of co-hydroprocessing of mix-vegetable oil and vacuumed gas oil is addressed and summarized as well. Overall, this review provides a comprehensive discussion on the hydrodeoxygenation issues and challenges in all relevant technical aspects.
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Abstract Malaysia is overdependence on fossil fuels as the primary source of energy. The issues related to environmental effects and energy security has driven the nation towards renewable energy, specifically biomass. The lignocellulosic... more
Abstract Malaysia is overdependence on fossil fuels as the primary source of energy. The issues related to environmental effects and energy security has driven the nation towards renewable energy, specifically biomass. The lignocellulosic biomass such as empty fruit bunches is potentially seen to replace fossil fuels because of its availability in Malaysia. In this study, torrefaction of empty fruit bunches was conducted in a tubular vertical reactor in inert atmosphere. The effect various torrefaction temperature (220, 260 and 300 °C) and time (30, 60 and 90 min) on the mass yield, calorific value and CHN analysis of empty fruit bunches was investigated. The activation energy for torrefaction of empty fruit bunches was 30.81 kJ/mol.
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Abstract The recent trends in biofuel research outcome mainly focused on the conversion of vegetable oil to the value added hydrocarbon fuels. Hydrodeoxygenation is one of the promising route for clean energy production. In this study,... more
Abstract The recent trends in biofuel research outcome mainly focused on the conversion of vegetable oil to the value added hydrocarbon fuels. Hydrodeoxygenation is one of the promising route for clean energy production. In this study, triolein was selected as the model compound representing rubber seed and jatropha seed oil to produce straight chain hydrocarbon. The thermodynamic equilibrium analysis was carried out using Aspen HYSYS software to study the thermodynamic interaction between hydrogen to triolein molar ratio, reaction pressure and temperature. The study revealed that thermodynamically, the optimum feed molar ratio of H2 to triolein is at 5:1 and pressure of 70 bar produced high amount of desired products, The selectivity for C18 decreases with the increased of temperature, as well as the ratio of C17/C18. The by products such as methane and propane are resulted from several side reactions, namely methanation, thermal cracking and reverse water gas shift reaction. This can possibly be minimized by using efficient and effective catalyst design.
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Abstract The physicochemical properties were studied to observe the influence of ultrasound irradiation on the synthesis of bimetallic solid acid catalyst (Ni-Mo/γ-Al 2 O 3 ). A set of catalyst was synthesized using conventional method... more
Abstract The physicochemical properties were studied to observe the influence of ultrasound irradiation on the synthesis of bimetallic solid acid catalyst (Ni-Mo/γ-Al 2 O 3 ). A set of catalyst was synthesized using conventional method and sonochemical method. The physicochemical characterizations were studied. The characterization techniques such as XRD, FESEM, EDX, TEM, BET surface area and temperature program reduction (H 2 -TPR) are highlighted in this manuscript. The XRD analysis revealed that with application of ultrasound irradiation, Ni-Mo particles are homogeneously distributed with the support in different crystal structures. The FESEM and TEM analysis confirmed that the nano catalyst synthesized via sonochemical method presents with average size of 15 nm i.e. smaller than the catalyst prepared via impregnation method. The BET surface area, pore size and pore volume also raised up to a certain level. H 2 -TPR profile showed lower reduction temperature 428 °C for sonochemically synthesized catalyst which assumed to be more active than conventionally synthesized catalyst.
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The studies based on morphological characterization to assess the effects of ultrasound irradiation on synthesis of solid acid catalysts. Three sets of catalyst formulation were synthesized by both wet impregnation method and ultrasound... more
The studies based on morphological characterization to assess the effects of ultrasound irradiation on synthesis of solid acid catalysts. Three sets of catalyst formulation were synthesized by both wet impregnation method and ultrasound assisted methods with different wt. % of Ni loading on γ-Al2O3. The XRD, BET, TEM and FESEM techniques were used to characterize the nano-particles. Physicochemical characterization revealed that the synthesized catalysts particles using ultrasound irradiation were in nano size range (1-24.5 nm) with equal dispersion of metal oxide, high surface area with increase of metal loading and high phase purity than the catalysts synthesized conventional method. These catalysts were also found in various crystal structures like cubic, monoclinic and tetrahedral. The use of ultrasound irradiation has great significance over the wet impregnation method in relation to the rate of synthesis of nanocatalysts. The high surface area, high thermal stability and small...
The carbon dioxide (CO2) dry reforming of glycerol for syngas production is one of the promising ways to benefit the oversupply crisis of glycerol worldwide. It is an attractive process as it converts carbon dioxide, a greenhouse gas into... more
The carbon dioxide (CO2) dry reforming of glycerol for syngas production is one of the promising ways to benefit the oversupply crisis of glycerol worldwide. It is an attractive process as it converts carbon dioxide, a greenhouse gas into a synthesis gas and simultaneously removed from the carbon biosphere cycle. In this study, the glycerol dry reforming was carried out using Silver (Ag) promoted Nickel (Ni) based catalysts supported on silicon oxide (SiO2) i.e. Ag-Ni/SiO2. The catalysts were prepared through wet impregnation method and characterized by using Brunauer-Emmett-Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Thermo Gravimetric (TGA) analysis. The experiment was conducted in a tubular reactor which condition fixed at 973 K and CO2:glycerol molar ratio of 1, under atmospheric pressure. It was found that the main gaseous products are H₂, CO and CH4 with H₂:CO molar ratio < 1.0. From the reaction study, Ag(5)-Ni/SiO2 results i...
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The objectives of this study were to investigate the most thermodynamically favoured reaction pathway during APR of sorbitol. The thermodynamic analysis of APR of sorbitol was studied using ASPEN Plus V8.0 by applying Gibbs free energy... more
The objectives of this study were to investigate the most thermodynamically favoured reaction pathway during APR of sorbitol. The thermodynamic analysis of APR of sorbitol was studied using ASPEN Plus V8.0 by applying Gibbs free energy minimization principle, operating at different temperatures (300–800 K), pressure (10–30 bar) and sorbitol concentration (1%, 3%, 5%, 10%, 15% and 20%). The simulation model was validated by comparing the results with the existing work conducted by Serentis and Tsiakaras. The results obtained show that the mol fraction and trend of H2, CO2 and CH4 for both cases are almost similar to the existing work. Therefore the simulation model was validated. Five main reaction pathways of APR of sorbitol were identified and intermediates of each reaction pathway were defined according to their stages and their composition was analyzed. The result obtained show that the decarbonylation reaction (pathway 2) is the most thermodynamically favoured pathway with a total dry basis percentage of 21%.
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Steam reforming of ethanol has been carried out using a commercial catalyst (Hi-FUEL) of calcium doped nickel/alumina catalyst. Hi-FUEL had successfully reformed ethanol into the desired products at relatively high yield and selectivity.... more
Steam reforming of ethanol has been carried out using a commercial catalyst (Hi-FUEL) of calcium doped nickel/alumina catalyst. Hi-FUEL had successfully reformed ethanol into the desired products at relatively high yield and selectivity. The hydrogen yield of 90.5% has been achieved from this catalyst with almost no ethylene detected. Hi-FUEL is also comparable with other calcium doped nickel/alumina catalyst as reported by other researchers.
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Fast depletion of fossil fuel coupled with its environmental unfriendliness is at the top of the world’s major issue, especially, in the energy industries. This study involves synthesis of catalyst for biodiesel production. Production of... more
Fast depletion of fossil fuel coupled with its environmental unfriendliness is at the top of the world’s major issue, especially, in the energy industries. This study involves synthesis of catalyst for biodiesel production. Production of biodiesel was carried out with the synthesized ceria based nanomaterial. The CeO2 TiO2 mixed metal oxides catalyst was synthesized by using impregnation method and characterized using FTIR, SAP, VPFESEM and Raman spectrometer. With palm oil feedstock of 0.11% free fatty acid (FFA), one-step transesterification was applied. The highest Biodiesel yield was 70.5%. This maximum yield was obtained at temperature, time, catalyst concentration and methanol oil ratio of 55°C, 150 min, 1% and 11.05:1 respectively. The reusability test showed that CeO2 TiO2 can be reused up to five times at maximum yield decrease of 3%.
The thermodynamic analysis of autothermal reforming of homologue series consisted of ethanol, ethylene glycol, propylene glycol and glycerol representing oxygenated hydrocarbons were studied. The main investigation was to compare the... more
The thermodynamic analysis of autothermal reforming of homologue series consisted of ethanol, ethylene glycol, propylene glycol and glycerol representing oxygenated hydrocarbons were studied. The main investigation was to compare the effect of thermoneutral condition where no external air/oxygen supplied for the reaction to sustain and controlled amount of air/oxygen supplied. It was found that the higher number of oxygen atoms in these homologues molecule, the higher tendency of the reaction to be sustained at the desired temperature, and thus it only requires lesser amount of air for heating. The hydrogen selectivity however depends on the ratio of hydrogen atoms with respect to the oxygen atoms in each molecule. The presence of air however, though providing extra heating to the reactor, is offset by a lower hydrogen production.